upgrade bug dilemna

Well, I've done it again... I've decided to upgrade.
current:
energy take2 mains
energy take1 center
no surround
energy encore sub
Onkyo tx-ds474 receiver
I want speakers to fill the gap better with that sub and give me more depth and clarity. I am thinking HTD level 3 mains and center.
Question is this: I'm tempted to get just the mains for now because then the take2's magically become surrounds. But, the center is really the most important channel, right? Then I'd have to sell my take1 center... and not get any surround... of course, i could just blow the bank and get both the mains and center... but i'm tempted to go slowly and get one or the other to start (in college, money tight and guilt high) Help me decide!
Jon

Spend? eh? Well, that is... I have enough to afford either the HTD level 3 mains or the level 3 center, but not both at once just yet.
I'm trying to decide which would be better off by itself in my current system until christmas when I can beg for the other as a gift. I am thinking probably mains since that would enable me to move the take2's to the rear. But can anyone convince me otherwise? Or suggest an even smarter speaker to go with my sub?
Has anyone looked at level 2? Maybe they'd work out better for my small dorm room space and budget? But would they be a serious improvement over my take2's?
Jon